Magnetocaloric effect in itinerant electron metamagnetic systems La(Fe1−xCox)11.9Si1.1

Abstract

The NaZn13-type compounds La(Fe1−xCox)11.9Si1.1 (x=0.04, 0.06, 0.08) were successfully synthesized, in which the Si content is the limit that can be reached by arc-melting technique. TC is tunable from 243 to 301 K with Co doping from x=0.04 to 0.08. Great magnetic entropy change ΔS in a wide temperature range from ∼230 to ∼320K has been observed. The adiabatic temperature change ΔTad upon changing magnetic field was also directly measured. ΔTad of sample x=0.06 reaches ∼2.4K upon a field change from 0 to 1.1 T. The temperature hysteresis upon phase transition is small, ∼1K, for all samples. The influence of Co doping on itinerant electron metamagnetic transition and magnetic entropy change is discussed.

Recent Progress in Exploring Magnetocaloric Materials

“…Figure 6a displays the entropy change as a function of temperature for decreases from ~23 J/kgK to ~15.6 J/kgK for a field change of 0-5T. [32] The study on the MCE of La 0.5 Pr 0.5 Fe 11.5-x Co x Si 1.5 (0≤x≤1.0) was performed by Shen et al [33] The substitution of Co in the Co 0.8 Si 1.5 was also studied. [34] As x grows from 0 to 0.5, the maximal value of entropy change increases from 13.5 to 14.6 J/kgK for a field change of 05 T, while T C , which is near room temperature, exhibits only a small change.…”

Effect of Al substitution on the magnetocaloric properties of La(Fe0.88Si0.12−xMorrison1, Подгорных2, Shcherbakova3 et al. 2011Phys. Rev. B170100View full textAdd to dashboardCite

“…5) to perform numerical summation as described in Eq. (5). If the change in heat capacity across the phase transition can be taken to be field independent, then the determination of T ad is much simpler, as described by Eq.…”

Evaluation of the reliability of the measurement of key magnetocaloric properties: A round robin study of La(Fe,Si,Mn)Hδ conducted by the SSEEC consortium of European laboratories

“…The balance between magnitude of the S and thermal and magnetic hysteresis (H) that result from materials which show first order character; the resulting adiabatic temperature change, ΔT ad, which is limited by the absolute magnitude of the heat capacity, C p , (Gschneidner et al 2005); and finally the magnitude of the magnetic field required to induce the transition which should be as small as possible due to the expense associated with producing rare earth permanent magnets (Humphries 2010;Schüler et al 2011). The La(Fe x Si 1-x ) 13 system appears to offer a unique combination of characteristics with large S of up to 30JK -1 kg -1 in field changes of 0-5 T, coupled with remarkably small hysteresis, ΔH, and a T c easily tuneable by interstitial addition of H (Fujita et al 2003;Lyubina et al 2008), or by doping with Co (Hu et al 2005;Lyubina et al 2008). Other advantages are cheap and abundant raw materials and easy preparation (Yan et al 2005) As the field grows the community is faced with a specific problem related to the reliability of measurement of the key physical properties M, S, C p and ΔT ad .…”